Signamax
™
065-7921PoE 12-Port 10/100/1000BaseT/TX Web Smart PoE Switch
67
4-2-8. Quality of Service Configuration
The
switch
offers powerful QoS function. This function supports VLAN-tagged priority
that can make precedence of 8 priorities, TOS field of IP header (equal DSCP High 3 bits) on
Layer 3 of network framework, 6 kinds of special network transmission events on Layer 4 and
IP DiffServe QoS service.
In Quality of Service (QoS) Configuration, there is one option named” Default Class”. As
you had selected one of the four QoS functions, then some packets that did not belong to this
QoS would be viewed as Default Class. For instance, if you set QoS function as VLAN Tag
Priority mode, and then choose Default Class as High, finally, the priority of the packets with
no tag will be considered as High priority precedence. The initial value of the Default Class is
High.
Fig. 4-14
Function name:
VLAN Tag Priority
Function description:
In vlan tag, there are 3 bits belonging to priority. According to these 3 bits, we could
arrange 8 traffics –0 0 0, 0 0 1, 0 1 0, 0 1 0, 1 0 0, 1 0 1, 1 1 0, 1 1 1. We can set High
priority or Low priority for each traffic class. For instance, if we let VLAN-tagged priority 0
0 0 be high priority and VLAN-tagged priority 0 0 1 be Low Priority, and then make port 1,
2, 3 be in the vlan 2. We sent in the packets that have vlan-tagged Field appears 0 0 0
and VID equals 2 from the port 2 and the packets that have vlan-tagged Field appears 0
0 1 and VID equals 2 from the port 3. We let the two kinds of packets be transmitted for
port 1 until the port results in congestion. The result is that the packets will be dropped
partially from the port 3 because the packets that belong to Low Priority. For the use of
VLAN Tag Priority function, please press Configure at the right section for setting in
advance.